Basement Review Draft policy and other measures for public consultation

1 1- Introduction

1.1 The Royal Borough of Kensington and Chelsea was probably the first local authority in the Country to produce a comprehensive set of planning policies to control basement development. The Council’s current policies are set out in the Subterranean Development Supplementary Planning Document (2009)[1] and within the Core Strategy (2010).[2]

1.2 The Council recognises that it is now time to review the relevant policies, and the associated procedures, in the light of its experience in operating its current policies.

1.3  This review has taken a number of strands.

    •  A review of the Council’s planning policy concerning basements, as set out within the Core Strategy (Section 2 below)
    •  A review of the contents of the Council’s guidance set out in the Subterranean Development Supplementary Planning Document, the document which puts flesh on the bones of the policies within the Core Strategy (Section 3 below)
    •  A review of the nature and timing of the submission of the documentation that the Council will require to as part of a planning application for a basement; (Section 4) and
    •  A review of the potential costs of bringing into planning control those basements that can at present be built without the need to submit a planning application (permitted development).  (Section 5)
1. A Supplementary Planning Document provides more information and detail on policies in the Core Strategy, and is approved by the Council’s Cabinet Member for Planning Policy. [back]
2. The Core Strategy sets out the Council’s vision and strategy for the Royal Borough and the core policies it believes are needed for that vision to be achieved. It forms the basis for the determination of planning applications. [back]

Timetable for the review

1.4 It is the review of planning policies in the Core Strategy that will largely drive the timetable as this is the starting point for determining planning applications.

1.5 The timetable for the review of the Core Strategy basement policy is set out below.

Issues and options

April/May 2012

Draft Policy(this stage)

December 2012/ January 2013


March/April 2013


June 2013

Examination in Public

September 2013

1.6  This paper is the second stage in the review process. It follows on from the ‘Basement: Issues’ paper which was published and consulted on in April and May of this year.

1.7 When we have received your views on the draft policies set out in this paper, we will make changes to the proposed policies. These policies will then be the subject of an independent examination likely to take place in September 2013.

1.8 We expect to have a new set of adopted policies in the Core Strategy by the end of 2013.

1.9 An amended version of the Council’s Subterranean Development Supplementary Planning Guidance will be drafted and consulted upon during 2013, to be adopted alongside the revised Core Strategy policies later in 2013.


What has informed the review?

Public consultation

1.10 Since the adoption of the Core Strategy, many residents have expressed concern about basement development. In order to allow these concerns to be more systematically considered, the Council has undertaken two strands of public consultation

1.11 The first is the response to the basement issues paper of April/ May this year.

1.12 The second is a direct survey targeted at those living next to, or close to, properties that have benefitted from basement extensions in the last three years.

1.13 Both consultations indicate that there is concern from a number of residents and amenity groups that the implementation of basement developments is having an unacceptable impact upon the living conditions of those living nearby. Of the 1350 neighbours who responded to the survey between 50% and 60% were concerned about the impact of construction noise, vibration and dust. 53% were concerned about construction traffic and a little over half noted an impact on their own property. Further detail was provided by additional surveys completed by a number of residents’ associations.

1.14 A lower proportion of neighbours appeared concerned about the impact of basement development on flooding and drainage, or indeed about the visual impact of completed basements beneath properties or their gardens.

1.15 The responses to the ‘Issues’ consultation earlier in 2012 raised similar issues.

1.16 Details of the responses for both the Issues consultation and the surveys are available on the Council’s website. A summary of the survey is contained at Appendix D.

Sustainability Appraisal

1.17 Any policies within the Core Strategy must be prepared with a view to contribute to the achievement of sustainable development. New policies must also be subject to a Sustainability Appraisal.

1.18 Sustainability Appraisals incorporate the requirements of the EU Strategic Environmental Assessment Directive. To this end the Council has carried out a Strategic Environmental Assessment/ Sustainability Appraisal on these draft policies. This appraisal has helped guide the decision making process. The SEA/SA report is available on the Council’s website. 


Alan Baxter Associates: Basement Report

1.19 In the summer of 2012 the Council commissioned Alan Baxter Associates to prepare a report to consider the impact of basement development on the wider area. This included consideration of structural stability, of hydrology, of environmental sustainability, and of the impact of the construction phase of a basement development. 

1.20 It sets out those issues and factors that need to be understood and considered when a basement is proposed if that basement is not to have a detrimental impact on the wider area.

1.21 The report in itself does not form part of the Council’s policy. It has, however, been used to inform the policy and the associated process. It is also likely to be of value to those planning basements, and those who are neighbours of basement developments. It is available on the Council’s website.

Basement development and the Planning regime

1.22 Planning is primarily designed to assess the final physical form and use of a proposed development. Construction impact is not normally regarded as a planning matter, but where basements are under construction in a residential street, the extent and duration of construction can have a major long term effect on residential living conditions. The Council exercises powers of control under environmental protection, control of pollution and highways legislation. It also attaches appropriate conditions to planning permissions to mitigate impact. Damage to a property by a neighbour is a civil matter and is normally dealt with through the Party Wall Act.

1.23 Planning applications cannot be assessed against criteria set out in other legislation.